KUSA-A1 mesenchymal stem cells response to PEEK-Si3N4 composites

Poly-Ether-Ether-Ketone (PEEK) is a structural biopolymer with various biomedical applications, from spinal cages to dental prosthetics. Due its high chemical stability combined with good mechanical strength, PEEK is considered to be one of the most successful bio-inert polymers ever developed. In this work, a mixture of PEEK and β-Si₃N₄ was used to produce a composite material which combined the mechanical properties of the polymer with the bioactive effects of a reinforcing ceramic, in particular its good osteoconductivity. When tested with KUSA-A1 mesenchymal cells, the composite material resulted in a higher production of bone tissue when compared to standard PEEK or biomedical titanium alloy. On the other hand, the composite showed poor osteogenic differentiation as evaluated by ALP. Tests performed using various spectroscopic techniques showed that the bone tissue formed has a balanced mineral-to-matrix ratio, similar to that of healthy bone tissue.     

On the mechanism of the (3He,t) reaction

The (³He, t) reactions are investigated by means of the second-order perturbation method with the (³He-α-t) process and the ordinary DWBA term. The analyses are performed on the data of ⁴⁸Ca(³He, t)⁴⁸Sc(0⁰⁺, 2⁺, 4⁺, 6⁺), ⁹⁰Zr(³He, t)⁹⁰Nb(2⁺, 4⁺, 6⁺, 8⁺) and ^{46, 48, 50}Ti(³He, t)^{46, 48, 50}V(0⁺. The results show that the (⁺He-α-t) process is an important process in these reactions and a very good agreement between observed and calculated cross sections is obtained. The energy dependence of the cross section of the ⁹⁰Zr(³He, t)⁹⁰Nb(O⁺) reaction is also discussed.     

Harpagometabolins Ⅰ and Ⅱ, Two New Metabolites from Harpagoside by Human Intestinal Bacteria

The dried roots of ScrOPhularia ningpoensl's Hemsl. (radix scrophulariae) have been usedin traditional chinese medicine for replendish the vital essence and relieve pyogenicinflammation'. Iridoids such as a harpagoside are main constitUents of radix scrophulariae2. Until noW, the pharmacological effects of these iridoids were not clearlyunderstood. Biological transformation in the human intestinal tract can induce theconversion of the iridoids to more or less biologically active compounds. …     

New synthetic routes to biscarbonylbipyridinerhenium(I) complexes cis,trans-[Re(X2bpy)(CO)2(PR3)(Y)n+ (X2bpy = 4,4'-X2-2,2'-bipyridine) via photochemical ligand substitution reactions, and their photophysical and electrochemical properties

Photochemical ligand substitution of fac-[Re(X2bpy)(CO)3(PR3)]+ (X2bpy = 4,4'-X2-2,2'-bipyridine; X = Me, H, CF3; R = OEt, Ph) with acetonitrile quantitatively gave a new class of biscarbonyl complexes, cis,trans[Re(X2bpy)(CO)2(PR3)(MeCN)]+, coordinated with four different kinds of ligands. Similarly, other biscarbonylrhenium complexes, cis,trans-[Re(X2bpy)(CO)2(PR3)(Y)]n+ (n = 0, Y = Cl-; n = 1, Y = pyridine, PR'3), were synthesized in good yields via photochemical ligand substitution reactions. The structure of cis,trans-[Re(Me2bpy)(CO)2[P(OEt)3](PPh3)](PF6) was determined by X-ray analysis. Crystal data: C38H42N2O5F6P3Re, monoclinic, P2(1/a), a = 11.592(1) A, b = 30.953(4) A, c = 11.799(2) A, V = 4221.6(1) A3, Z = 4, 7813 reflections, R = 0.066. The biscarbonyl complexes with two phosphorus ligands were strongly emissive from their 3MLCT state with lifetimes of 20-640 ns in fluid solutions at room temperature. Only weak or no emission was observed in the cases Y = Cl-, MeCN, and pyridine. Electrochemical reduction of the biscarbonyl complexes with Y = Cl- and pyridine in MeCN resulted in efficient ligand substitution to give the solvento complexes cis,trans-[Re(X2bpy)(CO)2(PR3)(MeCN)]+.